Oil and Gas Occupational Safety and Health Regulations

12.6 (1) If a hazardous substance is likely to be produced by hot work in a confined space,

• (a) the confined space shall be ventilated in accordance with subsection (2); or

• (b) every employee who enters into, exits from and occupies the confined space shall use respiratory protective equipment that meets the requirements of section 13.7.

(2) If the requirements set out in subsection 12.2(1) have been maintained with the use of ventilation equipment, no person shall be granted access to the confined space unless

• (a) the ventilation equipment is

  • (i) equipped with an alarm that will, if the equipment fails, be activated automatically and be audible or visible to any person in the confined space, or

  • (ii) monitored by an employee who is in constant attendance at the equipment; and

• (b) in the event of a failure of the ventilation equipment, sufficient time is available for the person to escape from the confined space before

  • (i) the person’s exposure to or the concentration of a hazardous substance in the confined space exceeds the limit prescribed in paragraph 12.2(1)(a),

  • (ii) the concentration of airborne hazardous substances, other than chemical agents, in the confined space is hazardous to the safety or health of the person, or

  • (iii) the concentration of oxygen in the atmosphere ceases to meet the requirements of paragraph 12.2(1)(c).

(3) The employee referred to in subparagraph (2)(a)(ii) shall activate an alarm in the event of a failure of the ventilation equipment.